Carnot efficiency does apply, because it black-body radiates away energy as part of the process, and therefore is a simple heat engine to some degree. In fact, everything above absolute zero is, including fuel cells. They operate at lower temperature differences and therefore the effect is smaller, but it's there nonetheless.
> Numerous studies put the cost of electricity from PV solar [wikipedia.org
As one of the people that wrote the article you're quoting, perhaps I'll jump in here
> at about 2x-5x the cost from other sources
The price of power from any source is dominated by three things, the CAPEX or how much you payed to build it, the OPEX (or O&M) which includes fuel costs and maintenance, and the duty cycle, what percentage of the time it runs at its full rated power. So, for instance, if you run the calculation for a NG turbine you'll find that the average cost of generation today is around 5.5 cents/kWh. However, if that very same plant is used as a peaker, only running during the 25% of the time that you need it, the price suddenly goes to 20 cents - that's basically the definition.
One of the problems with comparing PV to other sources is that it is, by definition, a peaking source. So when you compare it to an NG turbine it looks terrible. But when you compare it to the very same turbine operating as a peak load, suddenly it doesn't look so bad at all. Right now, large scale systems in the US southwest would generate power about 20% of the time and that works out to about 10 cents/kWh. So by that means *solar power is already cheaper than natural gas* (and has been for about a year). That statement, of course, is entirely dependant on the NG system in question being run to provide the same pattern of power - but LOTS of them do.
If you look beyond the borders of the US, one finds that the *vast* majority of new generation is wind and pv, for just these reasons. There's already so much base load in most places we don't know what to do with it, peaking is the problem, and PV is a reasonable solution to maybe 1/3rd of that.
> No one in the energy business uses that term, it is completely useless.
I'm in the energy business, and we use it all the time. So does everyone else, like
The EIA: http://www.eia.gov/tools/faqs/what-capacity-factor The NRC: http://www.nrc.gov/reading-rm/basic-ref/glossary/capacity-factor-net.html NREL: http://www.nrel.gov/analysis/tech_cap_factor.html The RMI: http://www.rmi.org/rmi/Capacity%20Factor The EPA: http://www.epa.gov/airtransport/pdfs/TSD_capacity_factors_analysis_for_new_units_7-6-10.pdf
along with all sorts of universities, calculators, and any other source one looks at.
Always like to hear from the "experts" like yourself, thanks for the helpful post.
"Even thinking locally, with an efficient enough panel you'll still get meaningful energy output during a rain storm. It's not total darkness during these conditions, and supplemented with battery backup to even out the load during lean times you should be fine."
In particular, multi-junction cells like these ones do better than conventional cells under these circumstances. A conventional single-junction cell loses about 1/2 the energy available in blue light, which is what the panel sees when the sun isn't shining directly on it, either early/late day or under cloud.
Ummm, Scouts were formed in 1907 (or 1908, depending on your definition). That's just over a century, certainly not something one can call "centuries".
"But, what would I know"
Apparently not much? Seriously, what did you expect to a leading question like that.
I think Apple is looking for a mid-range device with all the power of a high-end model that they can build and sell in the millions without the slowdowns and delays they've always had in the past. The 5C is certainly well tuned for that.
That said, the article suggests surprise at self-canibalization, like Apple never thought of it. Umm, yeah, like nothing they've done in the last 12 years is anything remotely like this event
2.99 GJ is 830 kWh. My home burns about 12 to 25 a day, depending on the season. It would really take three months of power to burn a body? That seems high.
"So what you are saying is that a consortium of non-Samsung mutually opposed companies are colluding to build 400 million devices this year, selling them for perhaps $120 billion, and losing money on every one"
No, what he said is that a *group* of non-Samsung mutually opposed companies are *competing wildly* to build 400 million devices this year, selling them for perhaps $120 billion, and losing money on every one.
That's what a race to the bottom *is*. That there is a race to the bottom is undeniable, the numbers are posted widely every few months. Let's see
http://bit.ly/1ddvbxy
As you can see, with the exception of Apple and Samsung, everyone else is zero or negative. If you believe sprinkling Android sauce over Nokia would change anything, you've done nothing to suggest why.
"Did you bring enough of whatever that was you took"
Given that your message doesn't clearly state what it's taking offence to, flies in the face of widely reported facts, and doesn't even seem to be based on what he said in the first place, one might be inclined to cast sophomoric aspersions later in the thread, no?
No. The rest of the costs you mention are factored in through the OPEX lines, which add little on either the nuke or non-nuke side. In the case of nukes, the fuel costs are small but the decom costs are higher. In the case of NG the fuel costs are higher but the decom costs are low (not zero, as you seem to imply).
All estimates I've seen on real market costs for CO2 would not upset this balance much, NG would still be the lowest cost option, at least in the US. You can play with this yourself here:
http://www.nrel.gov/analysis/tech_lcoe.html
I've written an intro on how to use this for PV calcs, but you can combine it with info on that page to do nukes (or maybe I should write one on that?):
To put this in perspective, the apples to apples comparison would go something like this in terms of relative CAPEX outlays, based on recent proposals
nuke - $7 - $8/W NG turbine - $1/W coal plant - $2/W - this has been true for a *long* time industrial PV - $1.50 - $2.50/W (was $8 in 2008!) industrial wind - $1.50 - $2/W (starting to flatten out now)
Now of course things like wind and PV have lower capacity factors than nukes, perhaps 1/3rd - 1/4 for wind and about 1/6th to 1/5th for PV. But they cost 1/5 as much. And that's pretty much the end of the story as far as actual industry members are concerned - as opposed to the boosters of one tech vs. the other, who add in all sorts of other "requirements" which aren't.
So when you look at this, it should not be entirely surprising that last year the world put in about 44 GWp of wind, 32 GWp of PV, about 10 GWp of NG (this number is one of the most difficult to find) and *negative* 15 GWp of nukes.
The nuke industry is fond of claiming various conspiracy theories and "dumb citizens" for their woes, but the problem is much more fundamental. Until they can get the $/W down into the $4 range, you shouldn't expect to see many new builds except for areas with *serious* base load issues.
EPR's produce 1650 MWe, so this plant will produce 3.3 GWp. The price is put at "£14bn", that's 21.8 bU$, or about 6.6 USD a watt. And that's at *an existing site*. New sites would be much more expensive due to paperwork delays.
Clearly the nuclear renaissance estimates of $4.6 are too low, as this is the cheapest plant I've seen recently and it's still over $6. Darlington B was $8.25 (at least), Vogtle 3&4 are around $7.25, and Crystal River 6 came in around $11.
For those new to this, the price of power from fission is almost entirely a function of its capital cost, measured in dollars per watt. Anything above 5 is generally uneconomical, and with NG at $2/MBTU that number is almost certainly even lower, probably down around $3 or $4/W.
Uggg, did you actually read what you're quoting? Here, let me quote the explanation that accompanies the number you're quoting:
"With a complete combustion or fission"
Of course we don't have "complete fission", and only a percentage of the fuel undergoes conversion into power. Just below the number you quote is this statement:
"Thus, 1 kg natural uranium - following a corresponding enrichment and used for power generation in light water reactors - corresponds to nearly 10,000 kg of mineral oil or 14,000 kg of coal"
14 thousand is a much different number than 24 million.
If you're looking for big audacious things to do, how about going to Mars? It would cost about the same, or less, have infinitely more scientific value, increase rocketry much more than a GEO launch, and help avoid a species-ending event. SPSs, on the other hand, simply suck up money and return nothing.
Given the possible universe of "cool things to do", why would we pick this particular brain dead one?
"I was equally generous in guesstimates of transmission efficiency (trying to make the case FOR as best I could) but yeah, even though "in principle" microwave power transmission can be as high as 90% efficient, I'd be rather surprised if it averages 50%."
Yeah, this one is murder. The transmitter is about 70% efficient, the receiver about 90, and modern inverters are about 95%. So.70 x.90 x.95 = 59%
To all the kids reading this. LEARN F'ING MATH. It will save you from believing in all sorts of BS like this.
"because as prices creep down from $1/watt"
I put a dozen SolarWorld 230's on my garage in 2010. At that time the panels were $2.30 a watt, the Enphase M190's about $1 a watt, and the rest of the system probably cost another $1 because of a long wire run I had to pull.
Due to changes in the local laws (Ontario FIT) we're looking at bringing SolarWorld back (great panels) as a premium brand. Most likely we'd stock the 275's, and sell them around 95 cents.
Thats in THREE YEARS.
Running the numbers, at current pricing PV in Toronto runs about 20 cents/kWh. That's pretty astonishing, considering that that's the flat price over 20 years. You see, our current price for power is about 15 cents, but over 20 years of inflation that takes you to about 25 cents. That's parity.
I don't think anyone out there really sees this yet. PV has gone from something only the military and aerospace companies used to something that can power your house cheaper than the local power plant, and did that in less than a decade.
All of this space stuff is bogus. Simply look over the list of participants. Not a single one of them comes from the solar world or the power world more broadly. Each and every one of them is a space guy. This isn't about power, it's about finding excuses to build rockets.
"Substantial improvements in a variety of technologies would be needed for space to be as practical as ground."
This is the lottery fallacy.
For argument's sake, let's say there are 1000 technologies in an SPS system - rocket engines, solar cells, lightweight aerostructures, turbo pumps, new inverter topologies, etc.
The vast majority of the list of possible improvements improves both the ground and space-based systems. For instance, if you improve the performance of solar cells, then both the ground and space based systems will improve.
So in order to close the 4x gap between space and ground, you need to improve *only those things that are used only on the space version*.
And that's the lottery. Given equal chances of improvement in any of the technologies involved, the vast majority of those will not change the relative value of the two systems.
"I know this is an unpopular view on Slashdot, where atomic energy fans come together to bash all other technologies"
It's the same everywhere. And I really don't understand why. All logic suggests nuclear supporters should be equally supportive of solar as well. Bunker mentality?
"The cost per watt of the panels is order of $1 (probably less, at this scale). "
We sell 1st tier, 3rd party warranty panels for 69 cents RETAIL. Large-buy wholesale prices are around 50 cents right now.
"get ten times the power per square meter"
Raw numbers are about 8 times. But then you have to consider the lifetime of the panels (1/2) and the transmission losses (1/2) and you'll end up with the space panel making perhaps 2 times as much power at any given time, and 1/2 over it's lifetime.
"It seems like the fear of weaponisation is whats kept this sort of thing from being explored more fully"
Oh gebus, no. What's keeping these things from being explored is that anyone with a pocket calculator can easily determine that it can not possibly work.
Slashdot Mirror
Carnot efficiency does apply, because it black-body radiates away energy as part of the process, and therefore is a simple heat engine to some degree. In fact, everything above absolute zero is, including fuel cells. They operate at lower temperature differences and therefore the effect is smaller, but it's there nonetheless.
Further reading:
https://en.wikipedia.org/wiki/Shockley-Queisser_limit
> Numerous studies put the cost of electricity from PV solar [wikipedia.org
As one of the people that wrote the article you're quoting, perhaps I'll jump in here
> at about 2x-5x the cost from other sources
The price of power from any source is dominated by three things, the CAPEX or how much you payed to build it, the OPEX (or O&M) which includes fuel costs and maintenance, and the duty cycle, what percentage of the time it runs at its full rated power. So, for instance, if you run the calculation for a NG turbine you'll find that the average cost of generation today is around 5.5 cents/kWh. However, if that very same plant is used as a peaker, only running during the 25% of the time that you need it, the price suddenly goes to 20 cents - that's basically the definition.
One of the problems with comparing PV to other sources is that it is, by definition, a peaking source. So when you compare it to an NG turbine it looks terrible. But when you compare it to the very same turbine operating as a peak load, suddenly it doesn't look so bad at all. Right now, large scale systems in the US southwest would generate power about 20% of the time and that works out to about 10 cents/kWh. So by that means *solar power is already cheaper than natural gas* (and has been for about a year). That statement, of course, is entirely dependant on the NG system in question being run to provide the same pattern of power - but LOTS of them do.
If you look beyond the borders of the US, one finds that the *vast* majority of new generation is wind and pv, for just these reasons. There's already so much base load in most places we don't know what to do with it, peaking is the problem, and PV is a reasonable solution to maybe 1/3rd of that.
> No one in the energy business uses that term, it is completely useless.
I'm in the energy business, and we use it all the time. So does everyone else, like
The EIA: http://www.eia.gov/tools/faqs/what-capacity-factor
The NRC: http://www.nrc.gov/reading-rm/basic-ref/glossary/capacity-factor-net.html
NREL: http://www.nrel.gov/analysis/tech_cap_factor.html
The RMI: http://www.rmi.org/rmi/Capacity%20Factor
The EPA: http://www.epa.gov/airtransport/pdfs/TSD_capacity_factors_analysis_for_new_units_7-6-10.pdf
along with all sorts of universities, calculators, and any other source one looks at.
Always like to hear from the "experts" like yourself, thanks for the helpful post.
> Why is it none of these ever make it to manufacture
They've been in manufacturing for years. They've simply improved the design.
It's like someone made a faster car, and you use this to claim no one builds any cars.
"Even thinking locally, with an efficient enough panel you'll still get meaningful energy output during a rain storm. It's not total darkness during these conditions, and supplemented with battery backup to even out the load during lean times you should be fine."
In particular, multi-junction cells like these ones do better than conventional cells under these circumstances. A conventional single-junction cell loses about 1/2 the energy available in blue light, which is what the panel sees when the sun isn't shining directly on it, either early/late day or under cloud.
I want to start the Lawyer Scouts of America.
Lets see them sue that.
"They've been using Scouts for centuries"
Ummm, Scouts were formed in 1907 (or 1908, depending on your definition). That's just over a century, certainly not something one can call "centuries".
"But, what would I know"
Apparently not much? Seriously, what did you expect to a leading question like that.
"to go with the 5C rather than the 4S"
Agree.
"about getting corporates to go"
Disagree.
I think Apple is looking for a mid-range device with all the power of a high-end model that they can build and sell in the millions without the slowdowns and delays they've always had in the past. The 5C is certainly well tuned for that.
That said, the article suggests surprise at self-canibalization, like Apple never thought of it. Umm, yeah, like nothing they've done in the last 12 years is anything remotely like this event
2.99 GJ is 830 kWh. My home burns about 12 to 25 a day, depending on the season. It would really take three months of power to burn a body? That seems high.
"So what you are saying is that a consortium of non-Samsung mutually opposed companies are colluding to build 400 million devices this year, selling them for perhaps $120 billion, and losing money on every one"
No, what he said is that a *group* of non-Samsung mutually opposed companies are *competing wildly* to build 400 million devices this year, selling them for perhaps $120 billion, and losing money on every one.
That's what a race to the bottom *is*. That there is a race to the bottom is undeniable, the numbers are posted widely every few months. Let's see
http://bit.ly/1ddvbxy
As you can see, with the exception of Apple and Samsung, everyone else is zero or negative. If you believe sprinkling Android sauce over Nokia would change anything, you've done nothing to suggest why.
"Did you bring enough of whatever that was you took"
Given that your message doesn't clearly state what it's taking offence to, flies in the face of widely reported facts, and doesn't even seem to be based on what he said in the first place, one might be inclined to cast sophomoric aspersions later in the thread, no?
"Better to make something you can sell than something that there is no market for."
How do we know they can sell it?
Samsung has the mid-range market sewn up. Sony and a few others have the fancy-phone versions. A host of Chinese companies have the low end.
I'm happy to be surprised, but let me express my scepticism that this entirely new company can find any niche to operate within.
"take on former Nokia engineers and set them to building phones again — this time, running Android"
Nokia needed to innovate, and an example of this is to build the same phone everyone else is? Good luck with that.
> Isn't the comparison a bit unfair though
No. The rest of the costs you mention are factored in through the OPEX lines, which add little on either the nuke or non-nuke side. In the case of nukes, the fuel costs are small but the decom costs are higher. In the case of NG the fuel costs are higher but the decom costs are low (not zero, as you seem to imply).
All estimates I've seen on real market costs for CO2 would not upset this balance much, NG would still be the lowest cost option, at least in the US. You can play with this yourself here:
http://www.nrel.gov/analysis/tech_lcoe.html
I've written an intro on how to use this for PV calcs, but you can combine it with info on that page to do nukes (or maybe I should write one on that?):
http://matter2energy.wordpress.com/2013/04/17/grid-parity-in-ontario/
To put this in perspective, the apples to apples comparison would go something like this in terms of relative CAPEX outlays, based on recent proposals
nuke - $7 - $8/W
NG turbine - $1/W
coal plant - $2/W - this has been true for a *long* time
industrial PV - $1.50 - $2.50/W (was $8 in 2008!)
industrial wind - $1.50 - $2/W (starting to flatten out now)
Now of course things like wind and PV have lower capacity factors than nukes, perhaps 1/3rd - 1/4 for wind and about 1/6th to 1/5th for PV. But they cost 1/5 as much. And that's pretty much the end of the story as far as actual industry members are concerned - as opposed to the boosters of one tech vs. the other, who add in all sorts of other "requirements" which aren't.
So when you look at this, it should not be entirely surprising that last year the world put in about 44 GWp of wind, 32 GWp of PV, about 10 GWp of NG (this number is one of the most difficult to find) and *negative* 15 GWp of nukes.
The nuke industry is fond of claiming various conspiracy theories and "dumb citizens" for their woes, but the problem is much more fundamental. Until they can get the $/W down into the $4 range, you shouldn't expect to see many new builds except for areas with *serious* base load issues.
EPR's produce 1650 MWe, so this plant will produce 3.3 GWp. The price is put at "£14bn", that's 21.8 bU$, or about 6.6 USD a watt. And that's at *an existing site*. New sites would be much more expensive due to paperwork delays.
Clearly the nuclear renaissance estimates of $4.6 are too low, as this is the cheapest plant I've seen recently and it's still over $6. Darlington B was $8.25 (at least), Vogtle 3&4 are around $7.25, and Crystal River 6 came in around $11.
For those new to this, the price of power from fission is almost entirely a function of its capital cost, measured in dollars per watt. Anything above 5 is generally uneconomical, and with NG at $2/MBTU that number is almost certainly even lower, probably down around $3 or $4/W.
"It's all just an attempt from NSA and CIA to create more news, driving attention from Snowden's leaks"
Riiiight, THIS is the story they created for that.
*coff* twerp *coff*
"What would you say on that, cold fjord, eh?"
Do you mean fnord?
> 1kg of uranium can generate 24,000,000 kWh
Uggg, did you actually read what you're quoting? Here, let me quote the explanation that accompanies the number you're quoting:
"With a complete combustion or fission"
Of course we don't have "complete fission", and only a percentage of the fuel undergoes conversion into power. Just below the number you quote is this statement:
"Thus, 1 kg natural uranium - following a corresponding enrichment and used for power generation in light water reactors - corresponds to nearly 10,000 kg of mineral oil or 14,000 kg of coal"
14 thousand is a much different number than 24 million.
"More like 15-25%. Same goes for cell lifetime which also clobbers Earth-side solar cells too"
No, 1/2. The transmitter is about 70%, the receiver about 90 and the inverters about 95.
70 x 90 x 95 = 59% ~= 1/2
"Same goes for cell lifetime which also clobbers Earth-side solar cells too"
LOLZ. Which do you think is more hostile to long-term survival of solar cells, outer space, or Nevada? Use Google, prove your conclusion.
"It may be bizarre, but it is a mostly correct observation"
Not even remotely. Do the math, or if you don't know how, Google it. here, I'll save you the trouble:
http://matter2energy.wordpress.com/2012/03/17/the-maury-equation/
Long and short, unless launch costs are ~$10 a kg, you're losing money on an SPS.
I said:
"Which they "solve" by placing the ground stations in the middle of nowhere"
You said:
"called for the area under the microwave antenna to be pasture land"
Do you know many large pastures in downtown Manhattan?
No?
But you do know of some out in the country?
Far away from the load?
So you have to transport the power from the downlink to the load?
Thank you for playing.
"As a race, we need to do big, audacious things"
I'm all for it.
"This is one of them, It should be done"
If you're looking for big audacious things to do, how about going to Mars? It would cost about the same, or less, have infinitely more scientific value, increase rocketry much more than a GEO launch, and help avoid a species-ending event. SPSs, on the other hand, simply suck up money and return nothing.
Given the possible universe of "cool things to do", why would we pick this particular brain dead one?
"I was equally generous in guesstimates of transmission efficiency (trying to make the case FOR as best I could) but yeah, even though "in principle" microwave power transmission can be as high as 90% efficient, I'd be rather surprised if it averages 50%."
Yeah, this one is murder. The transmitter is about 70% efficient, the receiver about 90, and modern inverters are about 95%. So .70 x .90 x .95 = 59%
To all the kids reading this. LEARN F'ING MATH. It will save you from believing in all sorts of BS like this.
"because as prices creep down from $1/watt"
I put a dozen SolarWorld 230's on my garage in 2010. At that time the panels were $2.30 a watt, the Enphase M190's about $1 a watt, and the rest of the system probably cost another $1 because of a long wire run I had to pull.
Due to changes in the local laws (Ontario FIT) we're looking at bringing SolarWorld back (great panels) as a premium brand. Most likely we'd stock the 275's, and sell them around 95 cents.
Thats in THREE YEARS.
Running the numbers, at current pricing PV in Toronto runs about 20 cents/kWh. That's pretty astonishing, considering that that's the flat price over 20 years. You see, our current price for power is about 15 cents, but over 20 years of inflation that takes you to about 25 cents. That's parity.
I don't think anyone out there really sees this yet. PV has gone from something only the military and aerospace companies used to something that can power your house cheaper than the local power plant, and did that in less than a decade.
All of this space stuff is bogus. Simply look over the list of participants. Not a single one of them comes from the solar world or the power world more broadly. Each and every one of them is a space guy. This isn't about power, it's about finding excuses to build rockets.
"Substantial improvements in a variety of technologies would be needed for space to be as practical as ground."
This is the lottery fallacy.
For argument's sake, let's say there are 1000 technologies in an SPS system - rocket engines, solar cells, lightweight aerostructures, turbo pumps, new inverter topologies, etc.
The vast majority of the list of possible improvements improves both the ground and space-based systems. For instance, if you improve the performance of solar cells, then both the ground and space based systems will improve.
So in order to close the 4x gap between space and ground, you need to improve *only those things that are used only on the space version*.
And that's the lottery. Given equal chances of improvement in any of the technologies involved, the vast majority of those will not change the relative value of the two systems.
> Average daily insolation is at least 4X better
And transmission losses take 1/2 of that.
Cell lifetime takes another 1/2.
> the fractional increase in cost of using high-tech panels is smaller
That is the most bizarre argument I've heard in a while.
"No one can possibly afford this car, so we may as well make it out of solid gold."
"I know this is an unpopular view on Slashdot, where atomic energy fans come together to bash all other technologies"
It's the same everywhere. And I really don't understand why. All logic suggests nuclear supporters should be equally supportive of solar as well. Bunker mentality?
http://matter2energy.wordpress.com/2013/02/19/why-solar-is-nuclears-best-friend/
"The cost per watt of the panels is order of $1 (probably less, at this scale). "
We sell 1st tier, 3rd party warranty panels for 69 cents RETAIL. Large-buy wholesale prices are around 50 cents right now.
"get ten times the power per square meter"
Raw numbers are about 8 times. But then you have to consider the lifetime of the panels (1/2) and the transmission losses (1/2) and you'll end up with the space panel making perhaps 2 times as much power at any given time, and 1/2 over it's lifetime.
"It seems like the fear of weaponisation is whats kept this sort of thing from being explored more fully"
Oh gebus, no. What's keeping these things from being explored is that anyone with a pocket calculator can easily determine that it can not possibly work.
http://matter2energy.wordpress.com/2012/03/17/the-maury-equation-redux/